Dental prophylactic device

ABSTRACT

A dental prophylactic device, commonly known as a prophy angle dental handpiece, for use by a dentist in cleaning a patient&#39;&#39;s teeth. The prophy angle herein comprises a disposable prophylactic dental handpiece containing a supply of abrasive paste and suitable means for delivering the paste progressively to a polishing cup projecting at right angles from the generally cylindrical body of the prophy angle.

United States Patent Deuschle DENTAL PROPHYLACTIC DEVICE 51 Sept. 19, 1972 3,472,045 10/1969 Nelsen et a1. ..32/59 X Primary Examiner-Robert Peshock Attorney-Hofgren, Wegner, Allen, Stellman & Mc- Cord [57] ABSTRACT A dental prophylactic device, commonly known as a prophy angle dental handpiece, for use by a dentist in cleaning a patients teeth. The prophy angle herein comprises a disposable prophylactic dental handpiece containing a supply of abrasive paste and suitable means for delivering the paste progressively to a polishing cup projecting at right angles from the generally cylindrical body of the prophy angle.

7 Claims, 5 Drawing Figures j 10 ew/5 W1 Z 44K// ll/I/l l I 5 17 z/r 13 r 2; 44 jZ/ vfizzj/g I DENTAL PROPIIYLACTIC DEVICE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to dental appliances and in I particular to prophy angles for use by dentists and the like in cleaning a patients teeth.

2. Description of the Prior Art A number of prophylactic devices have been developed for use by dentists in cleaning a patient's teeth. One conventional device comprises a suitable rotary brush adapted to be mounted on the end of the conventional drill and drive mechanism. The dentist conventionally picks up suitable paste from a cup by impressing the brush into the paste material in the cup and then. inserts the brush into the patients mouth to effect the brushing operation.

A more recent development comprehends the provision of a prophylactic dental device which may include a supply of the dental abrasive directly therein and which may be at least partially disposable upon completion of the cleaning of the' patients teeth. An example of such a self-contained prophylactic device is shown in US. Pat. No. 3,389,468 issued to Eugene W. Lewis et al. for Disposable Pre-Charged Dental Handpiece.

SUMMARY OF THE INVENTION The present invention comprehends an improved prophy angle dental handpiece generally similar to that shown in the Lewis et al patent but having improved means for delivering the abrasive paste to the polishing cup.

More specifically, the invention comprehends the provision in a prophy angle dental handpiece having a tubular housing and a polishing cup, means for mounting the polishing cup at an inner end of the housing for rotation about an axis perpendicular to the axis of the housing, and driven gear means carried for movement with the polishing cup, means for driving the driven gear means and for delivering abrasive paste through the housingto the polishing cup comprising an auger in the housing having an outer end adapted tobe rotated coaxially of the housing, an inner end defining a driver gear means meshing with the driven gear means for rotating the polishing cup as an incident of rotation of the outer end, and a torque transmitting and abrasive paste delivering portion extending between the outer and inner ends defined by a longitudinally extending carrier spaced radially outwardly of the axis of the housing, and a plurality of spaced, wedge-shaped projections extending radially outwardly of the carrier to the inner surface of the housing for urging the abrasive paste longitudinally through the housing to the inner end of the housing and the polishing cup, each projection narrowing toward the inner end of the carrier. The auger may include a plurality of segmentally helical walls at the outer end of the carrier projecting radially outwardly from the carrier to the inner surface of the housing for scraping the abrasive paste from the inner surface and urging the abrasive paste longitudinally toward the inner end of the housing.

Still further the auger may include a plurality of wedge-shaped projections extending radially outwardly from the inner end of the auger to the inner surface of the housing for urging the abrasive paste through the inner end of the housing to the polishing cup.

The auger further may be provided with a tubular sleeve at the inner end journalled on a tubular support in the housing with the driven gear being carried on a cylindrical axial portion concentrically within the tube support of the housing whereby the walls, the wedgeshaped projections, and the tubular sleeve cooperate to effectively preclude movement of the abrasive paste to the driven gear thereby to preclude undesirable wear of the carrier during operation of the prophy angle.

The prophy angle dental handpiece of the present invention is extremely simple and economical of construction while yet providing an improved delivery of the abrasive paste to the polishing cup with effectively minimized wear of the carrier means for rotating the polishing cup at the end of the handpiece.

BRIEF DESCRIITION OF THE DRAWING Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawing wherein:

FIG. 4 is a transverse section taken substantially along the line 4-4 of FIG. 2; and

FIG. 5 is a side elevation of the auger element thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the exemplary embodiment of the invention as disclosed in the drawing, a dental handpiece generally designated 10 is shown to comprise a prophy angle device suitable for use by a dentist or the like for cleaning and polishing a patients teeth. In the illustrative embodiment, the prophy angle comprises a disposable device formed of a low-cost material, such as plastic, and containing a suitable body of abrasive paste (not shown) for progressive delivery to a polishing cup 11 provided at one end of a cylindrical body portion of the device. The body portion 12 containing the supply of abrasive paste includes a rear portion 13 and a forward portion 14 provided with suitable transfer means generally designated 15 for transferring the paste progressively from portions 13 and 14 to the cup 11 during the teeth cleaning and polishing operation. Prophy angle 10 is adapted to be mounted on the conventional dental drill mechanism and includes an input shaft 16 driven by the drill mechanism for operating the paste transfer means and rotating the polishing cup. The paste transferring means further serves as means for transferring force from the shaft 16 to the polishing cup to effect the desired rotation thereof.

Forward portion 14 of body portion 12 defines a tubular housing having suitable support means 17 for receiving and holding a tubular bearing 18 at the distal end of which is a rotatably mounted cup 11. The portion 14 also has an internal bearing means 19 for journalling the distal end 20 of transfer means 15.

Transfer means 15 herein comprises'an auger having formed integrally therewith at one end the input shaft 16 and a driver gear 21 at the opposite end thereof adapted to mesh with a driven gear 22 having a tubular rows parallel to the axis 26 of body portion 12. Each projection is triangular in plan, as seen in FIG. 5, narrowing toward the inner end 20 of the carrier and defined by an outer planar surface 27 extending perpendicular to the housing axis 26. The circumferential surface of each projection 25 is arcuately shaped to conform to the inside curvature of the body portion 12. The outermost projection 28 includesa rearward extension 29 joined integrally with the innermost one of a plurality of segmentally spiral, axially spaced walls 30 projecting radially outwardly from the outer end of carrier 24. The proximal end 31 of the carrier defines a disc element provided with a plurality of lugs 32 correlated with the radial extension of walls 30 to center carrier end 31 on the axis 26 of housing 14, as shown in FIG. 4. Inner end 20 of auger comprises a radially outer tubular portion 33 adapted to encircle the outer end of tubular bearing 19 thereby to journal the inner end of auger 15 on bearing 19. Further, inner end defines a cylindrical base portion 34 mounting tubular portion 33 to the inner end of carrier 24 and further carrying a cylindrical axial portion 35 coaxially received within the outer end of bearing 19 to cooperate with tubular portion 33 in joumalling the carrier. Driver gear 21 comprises an inward extension of cylindrical axial portion 35. Tubular portion 33 further carries a plurality, herein three, of circumferentially spaced, elongated wedge-shaped projections 36 which narrow toward the inner end of forward portion 14 and include an outer radial surface 37, the projections extending parallel to the axis 26 of the housing at the outer end of base 34. A chamber 38 is provided at the inner end of housing portion 14 for channelling abrasive paste from the auger 15 to the polishing cup 11. A washer 40 is snapped into an internal groove 42 in the outer end of the housing for retaining auger 15 in position in the housing and for sealing the abrasive paste in the auger portion of the housing 12. In use, the device 10 is attached to the dental drill iirive mechanism with input shaft 16 being suitably engaged for rotation thereby. Rotation of shaft 16 causes rotation of the auger in a way to urge paste through housing portions 13 and 14, chamber 38, and tubular bearing 18 to the polishing cup 11. The helical walls 30 effectively scrape the inner surface of the housing and cause the abrasive paste to move axially inwardly to be next engaged by projections and be caused thereby to move further axially inwardly to the inner end of housing portion 14. The wedge-shaped projections 36 on the inner end of the auger complete the transfer of the abrasive paste to the chamber 38 at the inner end of housing portion 14 and thence to the polishing cup 11 through tubular carrier 18. The abrasive paste is effectively precluded from contacting the gearing 21, 22 by the effective seal provided between bearing 19 and auger portions 33 and 35 thereby effectively maximizing the useful life of the device notwithstanding the handling of highly abrasive polishing materials.

As shown in FIG. 5, auger 15 may comprise a single element having the input shaft 16 and driver gear 21 formed integrally therewith so that the auger may be formed by extremely low cost means such as injection molding. Housing portions 13 and 14 may similarly be formed of molded plastic and, thus, the prophy angle device 10 is extremely simple and economical of construction permitting a one-time disposable use thereof. Thus, illustratively, device 10 may be prepackaged with the abrasive paste therein, utilized for a single patient and discarded upon completion of the tooth cleaning operation at minimum cost. The feed of the abrasive paste to the polishing cup is positively and accurately effected as a result of the improved auger configuration. The device operates smoothly and efficiently to provide an improved facilitated cleaning of the patients teeth.

The foregoing disclosure of specific embodiments is illustrative of the broad inventive concepts comprehended by the invention.

Iclaim:

1. In a prophy angle dental handpiece having a tubular housing, a polishing cup, means for mounting the polishing cup at an inner end of the housing for rotation about an axis disposed at an angle with respect to the axis of the housing, and driven gear means carried for movement with said polishing cup,

means for driving said driven gear means and for delivering abrasive paste through said housing to said polishing cup comprising an auger in said housing having an outer end adapted to be rotated coaxially of said housing, an inner end defining a driver gear means meshing with said driven gear means for rotating said polishing cup as an incident of rotation of said outer end, and a torque transmitting and abrasive paste delivering portion extending between said outer and inner ends of the auger defined by a longitudinally extending carrier spaced from, but parallel to the longitudinal axis of said housing, said carrier being rotatable around the longitudinal axis of the housing and having a plurality of spaced projections extending radially outwardly from said carrier substantially to the inner surface of said housing for urging the abrasive paste longitudinally through said housing to said inner end of the housing and said polishing cup, said carrier being substantially linear in an axial direction from one end thereof to the opposite end thereof, said torque transmitting and abrasive paste delivering portion extending circumferentially less than 180 about the longitudinal axis of said housing.

2. The invention as defined in claim 1 wherein said torque transmitting and abrasive paste delivering portion extends circumferentially approximately about the axis of said housing.

6. The invention as defined in claim 1 wherein said inner end of the auger further includes elongate wedgeshaped projections for moving abrasive paste toward said inner end of the housing.

7. The invention as defined in claim 1 wherein said inner end of the auger further includes an axial portion supported for rotation by part of said housing, and a tubular portion encircling said part for substantially preventing movement of abrasive paste to said driven gear means. 

1. In a prophy angle dental handpiece having a tubular housing, a polishing cup, means for mounting the polishing cup at an inner end of the housing for rotation about an axis disposed at an angle with respect to the axis of the housing, and driven gear means carried for movement with said polishing cup, means for driving said driven gear means and for delivering abrasive paste through said housing to said polishing cup comprising an auger in said housing having an outer end adapted to be rotated coaxially of said housing, an inner end defining a driver gear means meshing with said driven gear means for rotating said polishing cup as an incident of rotation of said outer end, and a torque transmitting and abrasive paste delivering portion extending between said outer and inner ends of the auger defined by a longitudinally extending carrier spaced from, but parallel to the longitudinal axis of said housing, said carrier being rotatable around the longitudinal axis of the housing and having a plurality of spaced projections extending radially outwardly from said carrier substantially to the inner surface of said housing for urging the abrasive paste longitudinally through said housing to said inner end of the housing and said polishing cup, said carrier being substantially linear in an axial direction from one end thereof to the opposite end thereof, said torque transmitting and abrasive paste delivering portion extending circumferentially less than 180* about the longitudinal axis of said housing.
 2. The invention as defined in claim 1 wherein said torque transmitting and abrasive paste delivering portion extends circumferentially approximately 90* about the axis of said housing.
 3. The invention as defined in claim 2 wherein said torque transmitting and abrasive paste delivering portion is substantially wholly within the same quadrant about the axis of the housing throughout its length.
 4. The invention as defined in claim 1 wherein said projections are wedge-shaped and each narrows toward said inner end of the auger.
 5. The invention as defined in claim 1 wherein said outer end of the auger has segmentally helical walls for urging abrasive paste toward said inner end of the housing.
 6. The invention as defined in claim 1 wherein said inner end of the auger further includes elongate wedge-shaped projections for moving abrasive paste toward said inner end of the housing.
 7. The invention as defined in claim 1 wherein said inner end of the auger further includes an axial portion supported for rotation by part of said housing, and a tubular portion encircling said part for substantially preventing movement of abrasive paste to said driven gear means. 